bspace - notes - category 'sysadmin'

mod_wsgi on os x

sunday, march 1st, 2009 5:20am

[This installation was so easy it may not seem worth the notes and output below. But over the years I've found it surprisingly useful to be able to refer back to notes such as this, and helpful to read others' detailed installation reports.]

On this page...

Goal
Sources of info
Starting setup
Plan
Install
Configure & test

Goal & motivation

I'll be developing more and more web-apps that call services, and unless I call them all via ajax -- which might actually be a good idea -- I'll bump into the development server's single-threaded limitation. And even if I do call the services via ajax I'll likely run into problems if I'm calling more than one service simultaneously -- although the ability of an ajax call to fail gracefully via a timeout and try its resource again would be a cool thing to learn how to implement.
Thinking about this off and on for the last few months, I recently came across a posting by the god of apache-python integration, Graham Dumpleton, about using mod_wsgi for development. This, on top of a slow solaris installation using mod_python (the slowness probably has more to do with the box than mod_python) give me the impetus to delve into this.
Finally, gsf's encouragement to check out mod_wsgi at code4lib 2009 made me bite the bullet.

Sources of info

Starting setup

python version 2.5.1, via:

birkinbox:~ birkin$ 
birkinbox:~ birkin$ python
Python 2.5.1 (r251:54863, Jan 13 2009, 10:26:13) 
[GCC 4.0.1 (Apple Inc. build 5465)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>>

apache version 2.2.9, via phpinfo():

apache2handler

Apache Version  Apache/2.2.9 (Unix) mod_ssl/2.2.9 OpenSSL/0.9.7l DAV/2 PHP/5.2.6
Apache API Version  20051115
Server Administrator  you@example.com
Hostname:Port ::1:0
User/Group  www(70)/70
Max Requests  Per Child: 0 - Keep Alive: on - Max Per Connection: 100
Timeouts  Connection: 300 - Keep-Alive: 5
Virtual Server  No
Server Root /usr
Loaded Modules  core prefork http_core mod_so mod_authn_file mod_authn_dbm mod_authn_anon mod_authn_dbd mod_authn_default mod_authz_host mod_authz_groupfile mod_authz_user mod_authz_dbm mod_authz_owner mod_authz_default mod_auth_basic mod_auth_digest mod_cache mod_disk_cache mod_mem_cache mod_dbd mod_dumpio mod_ext_filter mod_include mod_filter mod_deflate mod_log_config mod_log_forensic mod_logio mod_env mod_mime_magic mod_cern_meta mod_expires mod_headers mod_ident mod_usertrack mod_setenvif mod_version mod_proxy mod_proxy_connect mod_proxy_ftp mod_proxy_http mod_proxy_ajp mod_proxy_balancer mod_ssl mod_mime mod_dav mod_status mod_autoindex mod_asis mod_info mod_cgi mod_dav_fs mod_vhost_alias mod_negotiation mod_dir mod_imagemap mod_actions mod_speling mod_userdir mod_alias mod_rewrite mod_bonjour2 mod_php5

Requirement: Docs say "The GNU C compiler from the MacOS X Developer Toolkit bundle is required." -- I should be fine; developer stuff is installed.

Plan

Follow Quick installation guide, 'cause I've been living a good life recently.

Install

Got source code from the specified download page.
Selected single version listed (2.3)

Unstuff

birkinbox:~ birkin$ 
birkinbox:~ birkin$ mv /Users/birkin/Downloads/mod_wsgi-2.3.tar.gz /Developer_3rd/mod_wsgi-2.3.tar.gz
birkinbox:~ birkin$ 
birkinbox:~ birkin$ cd /Developer_3rd/
birkinbox:Developer_3rd birkin$ 
birkinbox:Developer_3rd birkin$ /usr/bin/tar xvfz ./mod_wsgi-2.3.tar.gz
mod_wsgi-2.3/
mod_wsgi-2.3/configure
mod_wsgi-2.3/configure.ac
mod_wsgi-2.3/LICENCE
mod_wsgi-2.3/Makefile-1.X.in
mod_wsgi-2.3/Makefile-2.X.in
mod_wsgi-2.3/mod_wsgi.c
mod_wsgi-2.3/README
birkinbox:Developer_3rd birkin$

Configure

birkinbox:Developer_3rd birkin$ 
birkinbox:Developer_3rd birkin$ cd ./mod_wsgi-2.3/
birkinbox:mod_wsgi-2.3 birkin$ 
birkinbox:mod_wsgi-2.3 birkin$ ls -alF
total 952
drwxr-xr-x@  9 birkin  admin     306 Aug 23  2008 ./
drwxr-xr-x  20 birkin  admin     680 Mar  2 08:16 ../
-rw-r--r--@  1 birkin  admin   11358 Jun 23  2007 LICENCE
-rw-r--r--@  1 birkin  admin    1195 Dec 13  2007 Makefile-1.X.in
-rw-r--r--@  1 birkin  admin    1247 Dec 13  2007 Makefile-2.X.in
-rw-r--r--@  1 birkin  admin   16440 Mar 13  2008 README
-rwxr-xr-x@  1 birkin  admin   78314 Dec 21  2007 configure*
-rw-r--r--@  1 birkin  admin    4151 Jan 24  2008 configure.ac
-rw-r--r--@  1 birkin  admin  352904 Aug 23  2008 mod_wsgi.c
birkinbox:mod_wsgi-2.3 birkin$ 
birkinbox:mod_wsgi-2.3 birkin$ ./configure 
checking for apxs2... no
checking for apxs... /usr/sbin/apxs
checking Apache version... 2.2.9
checking for python... /usr/bin/python
configure: creating ./config.status
config.status: creating Makefile
birkinbox:mod_wsgi-2.3 birkin$ 
birkinbox:mod_wsgi-2.3 birkin$ ls -alF
total 1032
drwxr-xr-x@ 13 birkin  admin     442 Mar  2 10:38 ./
drwxr-xr-x  20 birkin  admin     680 Mar  2 08:16 ../
-rw-r--r--@  1 birkin  admin   11358 Jun 23  2007 LICENCE
-rw-r--r--   1 birkin  admin    1559 Mar  2 10:38 Makefile
-rw-r--r--@  1 birkin  admin    1195 Dec 13  2007 Makefile-1.X.in
-rw-r--r--@  1 birkin  admin    1247 Dec 13  2007 Makefile-2.X.in
lrwxr-xr-x   1 birkin  admin      15 Mar  2 10:38 Makefile.in@ -> Makefile-2.X.in
-rw-r--r--@  1 birkin  admin   16440 Mar 13  2008 README
-rw-r--r--   1 birkin  admin    4474 Mar  2 10:38 config.log
-rwxr-xr-x   1 birkin  admin   20621 Mar  2 10:38 config.status*
-rwxr-xr-x@  1 birkin  admin   78314 Dec 21  2007 configure*
-rw-r--r--@  1 birkin  admin    4151 Jan 24  2008 configure.ac
-rw-r--r--@  1 birkin  admin  352904 Aug 23  2008 mod_wsgi.c
birkinbox:mod_wsgi-2.3 birkin$

So far so good.

Build

birkinbox:mod_wsgi-2.3 birkin$ 
birkinbox:mod_wsgi-2.3 birkin$ 
birkinbox:mod_wsgi-2.3 birkin$ make
/usr/sbin/apxs -c -I/System/Library/Frameworks/Python.framework/Versions/2.5/include/python2.5 -DNDEBUG -DMACOSX -DENABLE_DTRACE  -Wc,'-arch ppc7400' -Wc,'-arch ppc64' -Wc,'-arch i386' -Wc,'-arch x86_64' mod_wsgi.c -arch ppc7400 -arch ppc64 -arch i386 -arch x86_64 -Wl,-F/System/Library/Frameworks -framework Python -u _PyMac_Error -framework Python -ldl
/usr/share/apr-1/build-1/libtool --silent --mode=compile gcc    -DDARWIN -DSIGPROCMASK_SETS_THREAD_MASK -no-cpp-precomp  -I/usr/include/apache2  -I/usr/include/apr-1   -I/usr/include/apr-1  -arch ppc7400 -arch ppc64 -arch i386 -arch x86_64 -I/System/Library/Frameworks/Python.framework/Versions/2.5/include/python2.5 -DNDEBUG -DMACOSX -DENABLE_DTRACE  -c -o mod_wsgi.lo mod_wsgi.c && touch mod_wsgi.slo
/usr/share/apr-1/build-1/libtool --silent --mode=link gcc -o mod_wsgi.la  -rpath /usr/libexec/apache2 -module -avoid-version    mod_wsgi.lo -arch ppc7400 -arch ppc64 -arch i386 -arch x86_64 -Wl,-F/System/Library/Frameworks -framework Python -u _PyMac_Error -framework Python -ldl
birkinbox:mod_wsgi-2.3 birkin$ 
birkinbox:mod_wsgi-2.3 birkin$ ls -alF
total 2648
drwxr-xr-x@ 18 birkin  admin     612 Mar  2 11:26 ./
drwxr-xr-x  20 birkin  admin     680 Mar  2 08:16 ../
drwxr-xr-x   7 birkin  admin     238 Mar  2 11:26 .libs/
-rw-r--r--@  1 birkin  admin   11358 Jun 23  2007 LICENCE
-rw-r--r--   1 birkin  admin    1559 Mar  2 11:26 Makefile
-rw-r--r--@  1 birkin  admin    1195 Dec 13  2007 Makefile-1.X.in
-rw-r--r--@  1 birkin  admin    1247 Dec 13  2007 Makefile-2.X.in
lrwxr-xr-x   1 birkin  admin      15 Mar  2 11:26 Makefile.in@ -> Makefile-2.X.in
-rw-r--r--@  1 birkin  admin   16440 Mar 13  2008 README
-rw-r--r--   1 birkin  admin    4474 Mar  2 11:26 config.log
-rwxr-xr-x   1 birkin  admin   20621 Mar  2 11:26 config.status*
-rwxr-xr-x@  1 birkin  admin   78314 Dec 21  2007 configure*
-rw-r--r--@  1 birkin  admin    4151 Jan 24  2008 configure.ac
-rw-r--r--@  1 birkin  admin  352904 Aug 23  2008 mod_wsgi.c
-rw-r--r--   1 birkin  admin     800 Mar  2 11:26 mod_wsgi.la
-rw-r--r--   1 birkin  admin     315 Mar  2 11:26 mod_wsgi.lo
-rw-r--r--   1 birkin  admin  817180 Mar  2 11:26 mod_wsgi.o
-rw-r--r--   1 birkin  admin       0 Mar  2 11:26 mod_wsgi.slo
birkinbox:mod_wsgi-2.3 birkin$

Smooth! Confirm that mod_wsgi.so file exists (the point of the build):

birkinbox:mod_wsgi-2.3 birkin$ 
birkinbox:mod_wsgi-2.3 birkin$ ls -alF ./.libs/
total 4432
drwxr-xr-x   7 birkin  admin     238 Mar  2 11:26 ./
drwxr-xr-x@ 18 birkin  admin     612 Mar  2 11:26 ../
-rw-r--r--   1 birkin  admin  803768 Mar  2 11:26 mod_wsgi.a
lrwxr-xr-x   1 birkin  admin      14 Mar  2 11:26 mod_wsgi.la@ -> ../mod_wsgi.la
-rw-r--r--   1 birkin  admin     801 Mar  2 11:26 mod_wsgi.lai
-rw-r--r--   1 birkin  admin  817100 Mar  2 11:26 mod_wsgi.o
-rwxr-xr-x   1 birkin  admin  633872 Mar  2 11:26 mod_wsgi.so*
birkinbox:mod_wsgi-2.3 birkin$

Looks good.

Install

birkinbox:mod_wsgi-2.3 birkin$ 
birkinbox:mod_wsgi-2.3 birkin$ sudo make install
Password:
/usr/sbin/apxs -i -S LIBEXECDIR=/usr/libexec/apache2 -n 'mod_wsgi' mod_wsgi.la
/usr/share/httpd/build/instdso.sh SH_LIBTOOL='/usr/share/apr-1/build-1/libtool' mod_wsgi.la /usr/libexec/apache2
/usr/share/apr-1/build-1/libtool --mode=install cp mod_wsgi.la /usr/libexec/apache2/
cp .libs/mod_wsgi.so /usr/libexec/apache2/mod_wsgi.so
cp .libs/mod_wsgi.lai /usr/libexec/apache2/mod_wsgi.la
cp .libs/mod_wsgi.a /usr/libexec/apache2/mod_wsgi.a
ranlib /usr/libexec/apache2/mod_wsgi.a
chmod 644 /usr/libexec/apache2/mod_wsgi.a
----------------------------------------------------------------------
Libraries have been installed in:
   /usr/libexec/apache2

If you ever happen to want to link against installed libraries
in a given directory, LIBDIR, you must either use libtool, and
specify the full pathname of the library, or use the `-LLIBDIR'
flag during linking and do at least one of the following:
   - add LIBDIR to the `DYLD_LIBRARY_PATH' environment variable
     during execution

See any operating system documentation about shared libraries for
more information, such as the ld(1) and ld.so(8) manual pages.
----------------------------------------------------------------------
chmod 755 /usr/libexec/apache2/mod_wsgi.so
birkinbox:mod_wsgi-2.3 birkin$

Confirm the mod_wsgi.so file has been installed in '/usr/libexec/apache2', as specified in this line of my Makefile:

LIBEXECDIR = /usr/libexec/apache2

birkinbox:mod_wsgi-2.3 birkin$ 
birkinbox:mod_wsgi-2.3 birkin$ ls -alF /usr/libexec/apache2
total 81488
drwxr-xr-x  72 root  wheel      2448 Mar  2 11:35 ./
drwxr-xr-x  93 root  wheel      3162 Feb 12 16:44 ../
(...)
-rwxr-xr-x   1 root  wheel    633872 Mar  2 11:35 mod_wsgi.so*
birkinbox:mod_wsgi-2.3 birkin$

Nice, there it is at the bottom.

Load module into apache

I can never remember exactly where the httpd.conf file is.

birkinbox:mod_wsgi-2.3 birkin$ 
birkinbox:mod_wsgi-2.3 birkin$ locate 'httpd.conf'
(...)
/private/etc/apache2/httpd.conf
(...)
birkinbox:mod_wsgi-2.3 birkin$

First a backup:

birkinbox:apache2 birkin$ sudo cp ./httpd.conf ./2009-03-02_httpd.conf

Added to the LoadModule section:

# Added 2009-03-02
LoadModule wsgi_module libexec/apache2/mod_wsgi.so

Restart

birkinbox:apache2 birkin$ sudo apachectl restart

Clean up

birkinbox:apache2 birkin$ 
birkinbox:apache2 birkin$ cd /Developer_3rd/mod_wsgi-2.3
birkinbox:mod_wsgi-2.3 birkin$ 
birkinbox:mod_wsgi-2.3 birkin$ make clean
rm -rf .libs
rm -f mod_wsgi.o mod_wsgi.la mod_wsgi.lo mod_wsgi.slo mod_wsgi.loT
rm -f config.log config.status
rm -rf autom4te.cache
birkinbox:mod_wsgi-2.3 birkin$

Configure & test

Reference: 'Configuring An Application'. Docs recommend following this to verify that mod_wsgi is actually working properly.
Note: phpinfo() does indicate the module is loaded.
Note: docs state to follow these QuickConfiguration instructions before delving into the more thorough configuration docs.

Test app function & directories

Created, per instructions, test function in a file and enclosing directory:

birkinbox:repository birkin$ 
birkinbox:repository birkin$ cd /Users/birkin/Documents/Brown_Library/ModWsgiTest 
birkinbox:ModWsgiTest birkin$ 
birkinbox:ModWsgiTest birkin$ ls -alF
total 8
drwxr-xr-x   3 birkin  staff   102 Mar  2 15:54 ./
drwxr-xr-x  87 birkin  staff  2958 Mar  2 15:54 ../
-rw-r--r--@  1 birkin  staff   277 Mar  2 15:43 mod_wsgi_test.wsgi
birkinbox:ModWsgiTest birkin$ 
birkinbox:ModWsgiTest birkin$ cat ./mod_wsgi_test.wsgi 
def application(environ, start_response):
    status = '200 OK'
    output = 'Hello World!'
    response_headers = [('Content-type', 'text/plain'),
                        ('Content-Length', str(len(output)))]
    start_response(status, response_headers)
    return [output]
birkinbox:ModWsgiTest birkin$

httpd.conf file changes

The docs give some sample configuration:

<VirtualHost *:80>

  ServerName www.example.com
  ServerAlias example.com
  ServerAdmin webmaster@example.com

  DocumentRoot /usr/local/www/documents

  <Directory /usr/local/www/documents>
    Order allow,deny
    Allow from all
  </Directory>

  WSGIScriptAlias /myapp /usr/local/www/wsgi-scripts/myapp.wsgi

  <Directory /usr/local/www/wsgi-scripts>
    Order allow,deny
    Allow from all
  </Directory>

</VirtualHost>

My try will be:

<VirtualHost *:80>

  ServerName 127.0.0.1
  ServerAlias 127.0.0.1
  ServerAdmin birkin_diana@brown.edu

  DocumentRoot /Users/birkin/Sites

  <Directory /Users/birkin/Sites>
    Order allow,deny
    Allow from all
  </Directory>

  WSGIScriptAlias /myapp /Users/birkin/Documents/Brown_Library/ModWsgiTest/mod_wsgi_test.wsgi

  <Directory /Users/birkin/Documents/Brown_Library/ModWsgiTest>
    Order allow,deny
    Allow from all
  </Directory>

</VirtualHost>

Backup

birkinbox:~ birkin$ sudo cp /private/etc/apache2/httpd.conf /private/etc/apache2/2009-03-02b_httpd.conf

Make change and restart

birkinbox:~ birkin$ 
birkinbox:~ birkin$ sudo apachectl restart
Password:
birkinbox:~ birkin$

Well, no errors on restart.

Plain old 127.0.0.1 still yields the usual default page, which is good.

Trying 'myapp'...

birkinbox:~ birkin$ python
Python 2.5.1 (r251:54863, Jan 13 2009, 10:26:13) 
[GCC 4.0.1 (Apple Inc. build 5465)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> 
>>> import urllib
>>> 
>>> urllib.urlopen( 'http://127.0.0.1/myapp/' ).read()
'<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN">\n<html><head>\n<title>403 Forbidden</title>\n</head><body>\n<h1>Forbidden</h1>\n<p>You don\'t have permission to access /myapp/\non this server.</p>\n</body></html>\n'
>>>

Ok... no permission, but it seems to recognize it as a valid web-address at least -- that's a start!

Got it; problem is permissions on an enclosing folder...

drwx------@  81 birkin  staff     2754 Feb  4 16:03 Documents/

Test app function & directories #2

Follow instructions this time and create a fully-accessible directory:

birkinbox:~ birkin$ 
birkinbox:~ birkin$ mv /Users/birkin/Documents/Brown_Library/ModWsgiTest /Users/birkin/ModWsgiTest
birkinbox:~ birkin$ 
birkinbox:~ birkin$ ls -alF /Users/birkin/
total 1472
(...)
drwxr-xr-x    3 birkin  staff      102 Mar  2 17:03 ModWsgiTest/
(...)
birkinbox:~ birkin$

Backup httpd.conf:

birkinbox:~ birkin$ 
birkinbox:~ birkin$ ls -alF /private/etc/apache2/
total 256
(...)
-rw-r--r--    1 root  wheel  17614 Mar  1  2008 2008-03-02_httpd.conf
-rw-r--r--    1 root  wheel  17613 Mar  2 11:55 2009-03-02_httpd.conf
-rw-r--r--    1 root  wheel  17685 Mar  2 16:59 2009-03-02b_httpd.conf
(...)
-rw-r--r--    1 root  wheel  18156 Mar  2 17:08 httpd.conf
(...)
birkinbox:~ birkin$ 
birkinbox:~ birkin$ sudo cp /private/etc/apache2/httpd.conf /private/etc/apache2/2009-03-02c_httpd.conf
Password:
birkinbox:~ birkin$ 
birkinbox:~ birkin$ ls -alF /private/etc/apache2/
total 296
(...)
-rw-r--r--    1 root  wheel  17614 Mar  1  2008 2008-03-02_httpd.conf
-rw-r--r--    1 root  wheel  17613 Mar  2 11:55 2009-03-02_httpd.conf
-rw-r--r--    1 root  wheel  17685 Mar  2 16:59 2009-03-02b_httpd.conf
-rw-r--r--    1 root  wheel  18156 Mar  2 18:40 2009-03-02c_httpd.conf
(...)
-rw-r--r--    1 root  wheel  18156 Mar  2 17:08 httpd.conf
(...)
birkinbox:~ birkin$

Change httpd.conf; section now is:

<VirtualHost *:80>

    ServerName 127.0.0.1
    ServerAlias 127.0.0.1
    ServerAdmin birkin_diana@brown.edu

    DocumentRoot /Users/birkin/Sites

    <Directory /Users/birkin/Sites>
        Order allow,deny
        Allow from all
    </Directory>

    WSGIScriptAlias /myapp /Users/birkin/ModWsgiTest/mod_wsgi_test.wsgi

    <Directory /Users/birkin/ModWsgiTest>
        Order allow,deny
        Allow from all
    </Directory>

</VirtualHost>

Restart & test

birkinbox:~ birkin$ 
birkinbox:~ birkin$ sudo apachectl restart
birkinbox:~ birkin$ 
birkinbox:~ birkin$ python
Python 2.5.1 (r251:54863, Jan 13 2009, 10:26:13) 
[GCC 4.0.1 (Apple Inc. build 5465)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> 
>>> import urllib
>>> 
>>> urllib.urlopen( 'http://127.0.0.1/myapp/' ).read()
'Hello World!'
>>>

Success!!!

Comment »

bspace notes

mod_wsgi on os x

sunday, march 1st, 2009 5:20am

Goal & motivation

Sources of info

Starting setup

Plan

Install

Configure & test

Info

Categories